为提高小麦病害检测精度,实现将模型方便快速部署到移动端,该研究提出了一种基于改进YOLOv8的轻量化小麦病害检测方法。首先,使用PP-LCNet模型替换YOLOv8网络结构的骨干网络,并在骨干网络层引入深度可分离卷积(depthwise separable conv...为提高小麦病害检测精度,实现将模型方便快速部署到移动端,该研究提出了一种基于改进YOLOv8的轻量化小麦病害检测方法。首先,使用PP-LCNet模型替换YOLOv8网络结构的骨干网络,并在骨干网络层引入深度可分离卷积(depthwise separable convolution, DepthSepConv)结构,减少模型参数量,提升模型检测性能;其次,在颈部网络部分添加全局注意力机制(global attention mechanism, GAM)模块,强化特征中语义信息和位置信息,提高模型特征融合能力;然后,引入轻量级通用上采样内容感知重组(content-aware reassembly of features,CARAFE)模块,提高模型对重要特征的提取能力;最后,使用Wise-IoU(weighted interpolation of sequential evidence for intersection over union)边界损失函数代替原损失函数,提升网络边界框回归性能和对小目标病害的检测效果。试验结果表明,对于大田环境下所采集的小麦病害数据集,改进后模型的参数量及模型大小相比原YOLOv8n基线模型分别降低了12.5%和11.3%,同时精确度(precision)及平均精度均值(mean average precision,m AP)相较于原模型分别提高了4.5和1.9个百分点,优于其他对比目标检测算法,可为小麦病害检测无人机等移动端检测装备的部署和应用提供参考。展开更多
The primary synchronization signal and the secondary synchronization signal are respectively used to fulfill the subframe and frame synchronization in the long term evolution (LTE) systems. Based on the assumption t...The primary synchronization signal and the secondary synchronization signal are respectively used to fulfill the subframe and frame synchronization in the long term evolution (LTE) systems. Based on the assumption that the channel frequency response of the primary synchronization signal symbol is nearly the same as that of the secondary synchronization symbol in frequency division duplex-LTE (FDD-LTE), a new synchronization method is proposed. The frame synchronization success probability is simulated in different wireless channel models and the Mento-Carlo method is used in the simulation. Simulation results show that if the LMMSE channel estimation is adopted, the proposed method is robust at a low signal noise ratio (SNR) scenario and works well when cartier frequency offset and fast Fourier transform (FFT) window timing offset are considered in practical applications. The frame synchronization success probability can still exceed 99% with an SNR of 0 dB when the maximum Doppler shift is very large, which means that this robust frame synchronization method can be applicable in most mobile situations. Simulation results also show that the success probability of the proposed frame synchronization method is higher than that of the method which fulfills the frame synchronization through correlating the received secondary synchronization symbol with local sequences in practical applications.展开更多
AIM: To investigate whether increased intestinal permeability contributes to the pathogenesis and progress of nonalcoholic steatohepatitis by observing its dynamic change in rat models. METHODS: Rat models of nonalc...AIM: To investigate whether increased intestinal permeability contributes to the pathogenesis and progress of nonalcoholic steatohepatitis by observing its dynamic change in rat models. METHODS: Rat models of nonalcoholic steatohepatitis were established by giving a fat-rich diet. The rats were sacrificed at wk 8, 12 and 16 during the study. Rats fed with normal diet were taken as control. Plasma D-lactate, plasma diarnine oxidase, serum lipids and liver transarninases were measured in blood of the femoral artery. Hepatic steatosis and inflammation were assessed by haematoxylin-eosin staining. RESULTS: A rat model of nonalcoholic steatohepatitis was established successfully. Plasma D-lactate level in model group at wk 8, 12 and 16 and diarnine oxidase level in model group at wk 12, 16 increased significantly compared with those in control group. There were notable differences of D-lactate and diarnine oxidase level in model group between wk 8 and 12 as well as between wk 12 and 16. Serum lipids, liver transaminases and liver injury also increased with disease development CONCLUSION: Increased intestinal permeability caused by intestinal bacterial overgrowth and endotoxin-induced intestinal destruction exists in rats with nonalcoholic steatohepatitis, which may partially explain the pathogenesis and progress of this disease.展开更多
In order to overcome the phenomenon of image blur and edge loss in the process of collecting and transmitting medical image,a denoising method of medical image based on discrete wavelet transform(DWT)and modified medi...In order to overcome the phenomenon of image blur and edge loss in the process of collecting and transmitting medical image,a denoising method of medical image based on discrete wavelet transform(DWT)and modified median filter for medical image coupling denoising is proposed.The method is composed of four modules:image acquisition,image storage,image processing and image reconstruction.Image acquisition gets the medical image that contains Gaussian noise and impulse noise.Image storage includes the preservation of data and parameters of the original image and processed image.In the third module,the medical image is decomposed as four sub bands(LL,HL,LH,HH)by wavelet decomposition,where LL is low frequency,LH,HL,HH are respective for horizontal,vertical and in the diagonal line high frequency component.Using improved wavelet threshold to process high frequency coefficients and retain low frequency coefficients,the modified median filtering is performed on three high frequency sub bands after wavelet threshold processing.The last module is image reconstruction,which means getting the image after denoising by wavelet reconstruction.The advantage of this method is combining the advantages of median filter and wavelet to make the denoising effect better,not a simple combination of the two previous methods.With DWT and improved median filter coefficients coupling denoising,it is highly practical for high-precision medical images containing complex noises.The experimental results of proposed algorithm are compared with the results of median filter,wavelet transform,contourlet and DT-CWT,etc.According to visual evaluation index PSNR and SNR and Canny edge detection,in low noise images,PSNR and SNR increase by 10%–15%;in high noise images,PSNR and SNR increase by 2%–6%.The experimental results of the proposed algorithm achieved better acceptable results compared with other methods,which provides an important method for the diagnosis of medical condition.展开更多
The center cutter of a hard rock tunnel boring machine(TBM) is installed on the cutterhead at a small radius and thus bears complex side force.Given this fact,the formation mechanism and change law of the side force s...The center cutter of a hard rock tunnel boring machine(TBM) is installed on the cutterhead at a small radius and thus bears complex side force.Given this fact,the formation mechanism and change law of the side force suffered by the center cutter were studied.Based on the rock shear failure criterion in combination with the lateral rolling width,a model for predicting the average side force was set up.Besides,a numerical analysis model of the rock fragmentation of the center cutter was established,and the instantaneous load changing features were investigated.Results shows that the inner side of the center cutter can form lateral rolling annulus in rock during the rotary cutting process.The smaller the installation radius is,the greater the cutter side force will be.In a working condition,the side force of the innermost center cutter is 11.66 k N,while it decreases sharply when installation radius increases.Variation tends to be gentle when installation radius is larger than 500 mm,and the side force of the outermost center cutter is reduced to 0.74 k N.展开更多
[Objective] This study aimed to clone ubiquitin-conjugating enzyme gene TaUBC4 from different wheat cultivars and thus analyze their phylogenetic relationship.[Method] The UBC4 coding sequences were cloned through rev...[Objective] This study aimed to clone ubiquitin-conjugating enzyme gene TaUBC4 from different wheat cultivars and thus analyze their phylogenetic relationship.[Method] The UBC4 coding sequences were cloned through reverse transcription PCR (RT-PCR) from 21 wheat varieties.After sequencing,the UBC4 sequence in wheat cultivar Zhongguochun (GenBank accession No:M28059) was selected as the reference gene,to analyze the mutation frequency and evolutionary distance in the CDSs and corresponding amino acid sequences of the different wheat cultivars.Moreover,the phylogenetic tree based on the amino acid sequences of these TaUBC4 genes were constructed,involving the homologous sequences of TaUBC4 in eight other monocots.[Result] TaUBC4 sequence was highly conserved because the similarity in DNA sequences of the wheat varieties was over 94%,while that in amino acid sequence was over 96%.And the amino acid sequence difference only can be seen at two sites among some varieties.Phylogenetic tree constructed revealed the evolutionary relationships among these wheat varieties.[Conclusion] This study reveals the polymorphism and evolutionary characteristics in the nucleotide and amino acid sequences in different wheat varieties,which lays foundation for investigating the evolution and biological function of TaUBC4 gene.In addition,the phylogenetic tree constructed provides theoretical references for the classification of the wheat varieties with complicated background.展开更多
Under the special background of China, the cooperative innovation between different government-industry-university-research institutes plays an increasingly important role in the agricultural field. However, the exist...Under the special background of China, the cooperative innovation between different government-industry-university-research institutes plays an increasingly important role in the agricultural field. However, the existing literature has paid little attention to it. Considering the cooperation patents, published in the agriculture field stemming from the Full-text Database of China Patents as the study object, the spatial and institutional attribute of the authors as the data source, and by combining the social network and spatial econometrics analysis, this paper analyzes the structure evolution characteristics of cooperative innovation networks of agricultural government-industry-university-research institute in the city level of China in 1985–2014, based on the triple helix theory, with the influence factors discussed. This shows that, 1) since 1985, China's agricultural innovation level has been substantially increased, but the development degree of the cooperative innovation network is low, and the patent cooperation mainly relies on authors in the same unit; 2) enterprises play a leading role in the agricultural cooperative innovation. The effect of the government and hybrid organizations driven by the government is not obvious; 3) the cooperative innovation in the province and city dominates, and a multi-pole pattern has been formed. The cooperative innovation network structure evolves from a single helix empty core and double helix multi core to a double helix hierarchical network; 4) the city's science, education funding and personnel investment are key factors determining the agricultural cooperative innovation, while the agricultural development of the city presents slight negative impacts on it. The spatial mismatch of supply and demand is present in the technical cooperative innovation of China's agriculture. Therefore, the science enhancement and education investment to big agricultural provinces should be promptly implemented.展开更多
Objective: To study the clinical efficacy and methods of permanent implantation of radioactive I-125 seed in surgery for local advanced non small lung cancer (LANSCLC). Methods: From Apr. 2004 to Apr. 2006, the I-...Objective: To study the clinical efficacy and methods of permanent implantation of radioactive I-125 seed in surgery for local advanced non small lung cancer (LANSCLC). Methods: From Apr. 2004 to Apr. 2006, the I-125 seeds were implanted into 30 patients with LANSCLC in surgery. The numbers of seeds were 10-40. The chemotherapy was performed in 10 to 14 days after operation. Results: There was no operative death, and the distribution of seeds and complications were reviewed by CT and X-ray after treatment. The distribution of seeds was satisfactory in all patients. The complete response rate (CR) was 56.6% and the part response (PR) was 26.6%. The overall response rate was 83.3% after 4-24 months of surgery. There was no one occurred radiation pneumonia. Prospective efficacy await further follow-up. Conclusion: Permanent implantation of 1-125 seed in surgery for LANSCLC, is a safe and effective method with mild complications.展开更多
China's economic growth miracle despite complicated administrative approval formalities prompted us to raise the following question: ls it true that reforming administrative approval will promote economic growth? B...China's economic growth miracle despite complicated administrative approval formalities prompted us to raise the following question: ls it true that reforming administrative approval will promote economic growth? Based on our analysis on market entry, we discovered that reforming administrative approval will spur economic growth by reducing transaction cost for firms. Administrative approval may suppress social cost and propel China's economic growth; China's gradualist approval reforms may indeed propel economic growth by reducing transaction cost for firms. With the data of prefecture-level cities during 2000-2013 and data of companies listed on the SME board during 2010-2014, we tested the effects of approval reforms on economic growth and on transaction cost, and employed instrumental variable and PSM for the treatment of the endogeneity problem - all these tests led to robust and consistent results. Moreover, we discovered that difference in government policy implementation in the approval process is the root cause of corruption and rent seeking.展开更多
Thomas Hardy, one of the greatest British novelists in the 19th century. The Mayor of Casterbridge, which is usually regarded as one of the best novels for Thomas Hardy, has received different interpretations since it...Thomas Hardy, one of the greatest British novelists in the 19th century. The Mayor of Casterbridge, which is usually regarded as one of the best novels for Thomas Hardy, has received different interpretations since its publication. This thesis tries to explore novel from the perspective of Darwinsm and Social Darwinism. The spirit of Darwinism is expressed all through the novel. Thomas Hardy's firm adherence to Darwinism and social Darwinism is reflected in his design of the rise and fall of Henchard, and the competition between Henchard and Farfrae. The rise and fall of Henchard, the competition between Henchard and Farfrae are analyzed by employing the principle of adaptation and the principle of struggling for existence.展开更多
A path-based timing optimization algorithm for buffer insertion and simultaneous sizing is proposed. Firstly, candidate buffer insertion location and buffer size for each branch in a given routing path were obtained v...A path-based timing optimization algorithm for buffer insertion and simultaneous sizing is proposed. Firstly, candidate buffer insertion location and buffer size for each branch in a given routing path were obtained via localized timing optimization. Then, through evaluating each potential insertion against design objectives, potential optimal buffer insertion locations and sizes for the whole routing tree were determined. At last, by removing redundant buffer insertion operations which do not maximize S ( so ), given timing requirements are finally fulfilled through minimum number of buffers.展开更多
The study aimed to examine changes in trabecular bone microstructure (TBMS) during the period of 5 weeks after the injury in a rat model of spinal cord injury (SCI). Eight-week-old male Wistar rats underwent surgi...The study aimed to examine changes in trabecular bone microstructure (TBMS) during the period of 5 weeks after the injury in a rat model of spinal cord injury (SCI). Eight-week-old male Wistar rats underwent surgical transection of the lower thoracic spinal cord (SCI, n = 16) or sham operation (SHAM, n = 14). TBMS (tissue volume, bone volume, bone volume fraction, trabecular thickness, width, number, separation, connectivity density, and trabecular bone pattern factor), assessed using a micro-computed tomography, was deteriorated 1, 3 and 5 weeks after SCI. In addition, both bone mass and serum biochemical parameters were determined. Dry bone weight, ash weight, bone mineral content (BMC), and BMC/tissue-volume were significantly lower in the SCI group than in the SHAM group throughout the experimental period. Serum inorganic phosphate and alkaline phosphatase levels were significantly lower in the SCI group than in the SHAM group 1 week after the surgery. SCI resulted in rapid deterioration of both bone mass and microstructure. These changes appeared as early as 1 week after SCI. Based on the authors' results, it should be noted that in SCI patients, interventions for preventing bone loss should start as soon as possible after the injury.展开更多
This paper presents a deep neural network(DNN)-based speech enhancement algorithm based on the soft audible noise masking for the single-channel wind noise reduction. To reduce the low-frequency residual noise, the ps...This paper presents a deep neural network(DNN)-based speech enhancement algorithm based on the soft audible noise masking for the single-channel wind noise reduction. To reduce the low-frequency residual noise, the psychoacoustic model is adopted to calculate the masking threshold from the estimated clean speech spectrum. The gain for noise suppression is obtained based on soft audible noise masking by comparing the estimated wind noise spectrum with the masking threshold. To deal with the abruptly time-varying noisy signals, two separate DNN models are utilized to estimate the spectra of clean speech and wind noise components. Experimental results on the subjective and objective quality tests show that the proposed algorithm achieves the better performance compared with the conventional DNN-based wind noise reduction method.展开更多
[ Objective] To study growth-promoting effects of liposome-encapsulated porcine somatotropin (pST) and its sustained-release effects in mice. [ Method] The mice were randomly divided into experimental groups and con...[ Objective] To study growth-promoting effects of liposome-encapsulated porcine somatotropin (pST) and its sustained-release effects in mice. [ Method] The mice were randomly divided into experimental groups and control group. The mice in the experimental groups were respective- ly administrated with pST and liposome-encapsulated pST via intraperitoneal injection, and those in the control group were administrated with saline. They were weighed on Day 7, 14 and 28, and the growth rate was calculated. [ Result] The growth of mice had significant difference between the experiment groups and control group (P 〈 0.05), which indicated that the pST and liposome-encapsulated pST had growth-promoting effects in mice, and the liposome-encapsulated pST had sustained-release effects. [Condusion] The liposome-encapsulated pST can promote the growth of animal and its sustained-release peried is 7 d.展开更多
This paper aims at assessing the evolutionist and creationist conceptions of Brazilian teachers. The work is developed within the framework of the European project BIOHEAD-CITIZEN (biology, health and environmental e...This paper aims at assessing the evolutionist and creationist conceptions of Brazilian teachers. The work is developed within the framework of the European project BIOHEAD-CITIZEN (biology, health and environmental education for better citizenship), which takes into account that scientific knowledge and teachers' attitudes and values can influence the teaching practices. The large questionnaire BIOHEAD-CITIZEN, which was constructed to be applied in 19 countries in Europe, Africa and Middle East countries, was applied, in this study, to six groups of Brazilian teachers: primary school teachers, biology teachers and Portuguese language teachers and corresponding teachers-to-be. For this paper the answers to questions about evolution were used as dependent variables. Descriptive and multivariate analyses were carried out. Biology teachers and biology teachers-to-be gave more importance to the natural selection and the evolution process than the other groups of teachers. Comparing to the BIOHEAD-CITIZEN countries, the total Brazilian sample showed a higher percentage of creationist conceptions, particularly the Brazilian biology teachers and teachers-to-be. As discussed herein, this may not be an obstacle for teaching evolution as they accept both creationist and evolutionist concomitantly.展开更多
This paper computed the newest impact solutions of the potentially dangerous asteroid (99942) Apophis based on 4,138 optical observations from March 15.10789 UTC (Universal Time Coordinated), 2004 to February 28.0...This paper computed the newest impact solutions of the potentially dangerous asteroid (99942) Apophis based on 4,138 optical observations from March 15.10789 UTC (Universal Time Coordinated), 2004 to February 28.089569 UTC, 2014 and 20 radar observations from January 27, 2005 through March 15, 2013, as of June 20, 2014. Using the freely available the OrbFit software Package, this paper followed its orbit forward in the searching for close approaches with the Earth and possible impacts up to year 2116. With the different A2 non-gravitational parameter in the motion of the asteroid (99942) Apophis, this paper computed possible impact solutions using the JPL DE405 (Jet Propulsion Laboratory Development Ephemeris) and 25 additional massive perturbed asteroids. Additionally, this paper used weighing and selection methods adopted in the OrbFit software as prepared by the NEODyS (Near Earth Objects--Dynamical Side) Team. Moreover, this paper used method of computing the orbit of Apophis taking into account star catalog debiasing and an error model with assumed astrometric errors RMS (root mean square), deduced from the observational material of the given observatories. JPL's Sentry and NEODyS's CLOMMON2, two automatic monitoring systems routinely scanning for possible impacts in the next hundred years. Only for several dangerous asteroids presented results are computed with the non-gravitational parameters. This paper detected possible impacts of the asteroid (99942) Apophis only with the non-gravitational parameter, A2 〉 0. It was appeared that impacts in 2068, 2087, 2105 and in 2111 were possible only when Apophis rotated in prograde direction.展开更多
An imported wine purchasing model for medium and small size enterprises is presented based on analytic hierarchy process after analyzing the current purchasing condition of medium and small size enterprise for wine im...An imported wine purchasing model for medium and small size enterprises is presented based on analytic hierarchy process after analyzing the current purchasing condition of medium and small size enterprise for wine importing. This model is feasible and practical. It will support and assist the purchasing strategy for the enterprise when importing wine within a certain scope and provide the reference to the enterprise for decision-making.展开更多
文摘为提高小麦病害检测精度,实现将模型方便快速部署到移动端,该研究提出了一种基于改进YOLOv8的轻量化小麦病害检测方法。首先,使用PP-LCNet模型替换YOLOv8网络结构的骨干网络,并在骨干网络层引入深度可分离卷积(depthwise separable convolution, DepthSepConv)结构,减少模型参数量,提升模型检测性能;其次,在颈部网络部分添加全局注意力机制(global attention mechanism, GAM)模块,强化特征中语义信息和位置信息,提高模型特征融合能力;然后,引入轻量级通用上采样内容感知重组(content-aware reassembly of features,CARAFE)模块,提高模型对重要特征的提取能力;最后,使用Wise-IoU(weighted interpolation of sequential evidence for intersection over union)边界损失函数代替原损失函数,提升网络边界框回归性能和对小目标病害的检测效果。试验结果表明,对于大田环境下所采集的小麦病害数据集,改进后模型的参数量及模型大小相比原YOLOv8n基线模型分别降低了12.5%和11.3%,同时精确度(precision)及平均精度均值(mean average precision,m AP)相较于原模型分别提高了4.5和1.9个百分点,优于其他对比目标检测算法,可为小麦病害检测无人机等移动端检测装备的部署和应用提供参考。
文摘The primary synchronization signal and the secondary synchronization signal are respectively used to fulfill the subframe and frame synchronization in the long term evolution (LTE) systems. Based on the assumption that the channel frequency response of the primary synchronization signal symbol is nearly the same as that of the secondary synchronization symbol in frequency division duplex-LTE (FDD-LTE), a new synchronization method is proposed. The frame synchronization success probability is simulated in different wireless channel models and the Mento-Carlo method is used in the simulation. Simulation results show that if the LMMSE channel estimation is adopted, the proposed method is robust at a low signal noise ratio (SNR) scenario and works well when cartier frequency offset and fast Fourier transform (FFT) window timing offset are considered in practical applications. The frame synchronization success probability can still exceed 99% with an SNR of 0 dB when the maximum Doppler shift is very large, which means that this robust frame synchronization method can be applicable in most mobile situations. Simulation results also show that the success probability of the proposed frame synchronization method is higher than that of the method which fulfills the frame synchronization through correlating the received secondary synchronization symbol with local sequences in practical applications.
文摘AIM: To investigate whether increased intestinal permeability contributes to the pathogenesis and progress of nonalcoholic steatohepatitis by observing its dynamic change in rat models. METHODS: Rat models of nonalcoholic steatohepatitis were established by giving a fat-rich diet. The rats were sacrificed at wk 8, 12 and 16 during the study. Rats fed with normal diet were taken as control. Plasma D-lactate, plasma diarnine oxidase, serum lipids and liver transarninases were measured in blood of the femoral artery. Hepatic steatosis and inflammation were assessed by haematoxylin-eosin staining. RESULTS: A rat model of nonalcoholic steatohepatitis was established successfully. Plasma D-lactate level in model group at wk 8, 12 and 16 and diarnine oxidase level in model group at wk 12, 16 increased significantly compared with those in control group. There were notable differences of D-lactate and diarnine oxidase level in model group between wk 8 and 12 as well as between wk 12 and 16. Serum lipids, liver transaminases and liver injury also increased with disease development CONCLUSION: Increased intestinal permeability caused by intestinal bacterial overgrowth and endotoxin-induced intestinal destruction exists in rats with nonalcoholic steatohepatitis, which may partially explain the pathogenesis and progress of this disease.
基金Project(2016JJ4074)supported by the Natural Science Foundation of Hunan Province,ChinaProject(14C0920)supported by the Hunan Provincial Education Department,ChinaProject(61771191)supported by the National Natural Science Foundation of China
文摘In order to overcome the phenomenon of image blur and edge loss in the process of collecting and transmitting medical image,a denoising method of medical image based on discrete wavelet transform(DWT)and modified median filter for medical image coupling denoising is proposed.The method is composed of four modules:image acquisition,image storage,image processing and image reconstruction.Image acquisition gets the medical image that contains Gaussian noise and impulse noise.Image storage includes the preservation of data and parameters of the original image and processed image.In the third module,the medical image is decomposed as four sub bands(LL,HL,LH,HH)by wavelet decomposition,where LL is low frequency,LH,HL,HH are respective for horizontal,vertical and in the diagonal line high frequency component.Using improved wavelet threshold to process high frequency coefficients and retain low frequency coefficients,the modified median filtering is performed on three high frequency sub bands after wavelet threshold processing.The last module is image reconstruction,which means getting the image after denoising by wavelet reconstruction.The advantage of this method is combining the advantages of median filter and wavelet to make the denoising effect better,not a simple combination of the two previous methods.With DWT and improved median filter coefficients coupling denoising,it is highly practical for high-precision medical images containing complex noises.The experimental results of proposed algorithm are compared with the results of median filter,wavelet transform,contourlet and DT-CWT,etc.According to visual evaluation index PSNR and SNR and Canny edge detection,in low noise images,PSNR and SNR increase by 10%–15%;in high noise images,PSNR and SNR increase by 2%–6%.The experimental results of the proposed algorithm achieved better acceptable results compared with other methods,which provides an important method for the diagnosis of medical condition.
基金Project (2013CB035401) supported by the National Basic Research Program of ChinaProject (51475478) supported by the National Natural Science Foundation of ChinaProject (2012AA041803) supported by the High-Tech Research and Development Program of China
文摘The center cutter of a hard rock tunnel boring machine(TBM) is installed on the cutterhead at a small radius and thus bears complex side force.Given this fact,the formation mechanism and change law of the side force suffered by the center cutter were studied.Based on the rock shear failure criterion in combination with the lateral rolling width,a model for predicting the average side force was set up.Besides,a numerical analysis model of the rock fragmentation of the center cutter was established,and the instantaneous load changing features were investigated.Results shows that the inner side of the center cutter can form lateral rolling annulus in rock during the rotary cutting process.The smaller the installation radius is,the greater the cutter side force will be.In a working condition,the side force of the innermost center cutter is 11.66 k N,while it decreases sharply when installation radius increases.Variation tends to be gentle when installation radius is larger than 500 mm,and the side force of the outermost center cutter is reduced to 0.74 k N.
基金Supported by the Natural Science Foundation of Shandong Province(ZR2011CQ035)Scientific and Technological Innovation Fund for the Undergraduates of Liaocheng University(F2013274)~~
文摘[Objective] This study aimed to clone ubiquitin-conjugating enzyme gene TaUBC4 from different wheat cultivars and thus analyze their phylogenetic relationship.[Method] The UBC4 coding sequences were cloned through reverse transcription PCR (RT-PCR) from 21 wheat varieties.After sequencing,the UBC4 sequence in wheat cultivar Zhongguochun (GenBank accession No:M28059) was selected as the reference gene,to analyze the mutation frequency and evolutionary distance in the CDSs and corresponding amino acid sequences of the different wheat cultivars.Moreover,the phylogenetic tree based on the amino acid sequences of these TaUBC4 genes were constructed,involving the homologous sequences of TaUBC4 in eight other monocots.[Result] TaUBC4 sequence was highly conserved because the similarity in DNA sequences of the wheat varieties was over 94%,while that in amino acid sequence was over 96%.And the amino acid sequence difference only can be seen at two sites among some varieties.Phylogenetic tree constructed revealed the evolutionary relationships among these wheat varieties.[Conclusion] This study reveals the polymorphism and evolutionary characteristics in the nucleotide and amino acid sequences in different wheat varieties,which lays foundation for investigating the evolution and biological function of TaUBC4 gene.In addition,the phylogenetic tree constructed provides theoretical references for the classification of the wheat varieties with complicated background.
基金Under the auspices of National Natural Science Foundation of China(No.41471105,41430637,41701197)Program for Innovative Research Team(in Science and Technology)in University of Henan Province(No.16IRTSTHN012)+1 种基金Key Project of the Humanities and Social Sciences Research Base in Ministry of Education(No.15JJDZONGHE008)China Postdoctoral Science Foundation(No.2013M531667,2014T70672)
文摘Under the special background of China, the cooperative innovation between different government-industry-university-research institutes plays an increasingly important role in the agricultural field. However, the existing literature has paid little attention to it. Considering the cooperation patents, published in the agriculture field stemming from the Full-text Database of China Patents as the study object, the spatial and institutional attribute of the authors as the data source, and by combining the social network and spatial econometrics analysis, this paper analyzes the structure evolution characteristics of cooperative innovation networks of agricultural government-industry-university-research institute in the city level of China in 1985–2014, based on the triple helix theory, with the influence factors discussed. This shows that, 1) since 1985, China's agricultural innovation level has been substantially increased, but the development degree of the cooperative innovation network is low, and the patent cooperation mainly relies on authors in the same unit; 2) enterprises play a leading role in the agricultural cooperative innovation. The effect of the government and hybrid organizations driven by the government is not obvious; 3) the cooperative innovation in the province and city dominates, and a multi-pole pattern has been formed. The cooperative innovation network structure evolves from a single helix empty core and double helix multi core to a double helix hierarchical network; 4) the city's science, education funding and personnel investment are key factors determining the agricultural cooperative innovation, while the agricultural development of the city presents slight negative impacts on it. The spatial mismatch of supply and demand is present in the technical cooperative innovation of China's agriculture. Therefore, the science enhancement and education investment to big agricultural provinces should be promptly implemented.
文摘Objective: To study the clinical efficacy and methods of permanent implantation of radioactive I-125 seed in surgery for local advanced non small lung cancer (LANSCLC). Methods: From Apr. 2004 to Apr. 2006, the I-125 seeds were implanted into 30 patients with LANSCLC in surgery. The numbers of seeds were 10-40. The chemotherapy was performed in 10 to 14 days after operation. Results: There was no operative death, and the distribution of seeds and complications were reviewed by CT and X-ray after treatment. The distribution of seeds was satisfactory in all patients. The complete response rate (CR) was 56.6% and the part response (PR) was 26.6%. The overall response rate was 83.3% after 4-24 months of surgery. There was no one occurred radiation pneumonia. Prospective efficacy await further follow-up. Conclusion: Permanent implantation of 1-125 seed in surgery for LANSCLC, is a safe and effective method with mild complications.
文摘China's economic growth miracle despite complicated administrative approval formalities prompted us to raise the following question: ls it true that reforming administrative approval will promote economic growth? Based on our analysis on market entry, we discovered that reforming administrative approval will spur economic growth by reducing transaction cost for firms. Administrative approval may suppress social cost and propel China's economic growth; China's gradualist approval reforms may indeed propel economic growth by reducing transaction cost for firms. With the data of prefecture-level cities during 2000-2013 and data of companies listed on the SME board during 2010-2014, we tested the effects of approval reforms on economic growth and on transaction cost, and employed instrumental variable and PSM for the treatment of the endogeneity problem - all these tests led to robust and consistent results. Moreover, we discovered that difference in government policy implementation in the approval process is the root cause of corruption and rent seeking.
文摘Thomas Hardy, one of the greatest British novelists in the 19th century. The Mayor of Casterbridge, which is usually regarded as one of the best novels for Thomas Hardy, has received different interpretations since its publication. This thesis tries to explore novel from the perspective of Darwinsm and Social Darwinism. The spirit of Darwinism is expressed all through the novel. Thomas Hardy's firm adherence to Darwinism and social Darwinism is reflected in his design of the rise and fall of Henchard, and the competition between Henchard and Farfrae. The rise and fall of Henchard, the competition between Henchard and Farfrae are analyzed by employing the principle of adaptation and the principle of struggling for existence.
文摘A path-based timing optimization algorithm for buffer insertion and simultaneous sizing is proposed. Firstly, candidate buffer insertion location and buffer size for each branch in a given routing path were obtained via localized timing optimization. Then, through evaluating each potential insertion against design objectives, potential optimal buffer insertion locations and sizes for the whole routing tree were determined. At last, by removing redundant buffer insertion operations which do not maximize S ( so ), given timing requirements are finally fulfilled through minimum number of buffers.
文摘The study aimed to examine changes in trabecular bone microstructure (TBMS) during the period of 5 weeks after the injury in a rat model of spinal cord injury (SCI). Eight-week-old male Wistar rats underwent surgical transection of the lower thoracic spinal cord (SCI, n = 16) or sham operation (SHAM, n = 14). TBMS (tissue volume, bone volume, bone volume fraction, trabecular thickness, width, number, separation, connectivity density, and trabecular bone pattern factor), assessed using a micro-computed tomography, was deteriorated 1, 3 and 5 weeks after SCI. In addition, both bone mass and serum biochemical parameters were determined. Dry bone weight, ash weight, bone mineral content (BMC), and BMC/tissue-volume were significantly lower in the SCI group than in the SHAM group throughout the experimental period. Serum inorganic phosphate and alkaline phosphatase levels were significantly lower in the SCI group than in the SHAM group 1 week after the surgery. SCI resulted in rapid deterioration of both bone mass and microstructure. These changes appeared as early as 1 week after SCI. Based on the authors' results, it should be noted that in SCI patients, interventions for preventing bone loss should start as soon as possible after the injury.
基金partially supported by the National Natural Science Foundation of China (Nos.11590772, 11590770)the Pre-research Project for Equipment of General Information System (No.JZX2017-0994/Y306)
文摘This paper presents a deep neural network(DNN)-based speech enhancement algorithm based on the soft audible noise masking for the single-channel wind noise reduction. To reduce the low-frequency residual noise, the psychoacoustic model is adopted to calculate the masking threshold from the estimated clean speech spectrum. The gain for noise suppression is obtained based on soft audible noise masking by comparing the estimated wind noise spectrum with the masking threshold. To deal with the abruptly time-varying noisy signals, two separate DNN models are utilized to estimate the spectra of clean speech and wind noise components. Experimental results on the subjective and objective quality tests show that the proposed algorithm achieves the better performance compared with the conventional DNN-based wind noise reduction method.
文摘[ Objective] To study growth-promoting effects of liposome-encapsulated porcine somatotropin (pST) and its sustained-release effects in mice. [ Method] The mice were randomly divided into experimental groups and control group. The mice in the experimental groups were respective- ly administrated with pST and liposome-encapsulated pST via intraperitoneal injection, and those in the control group were administrated with saline. They were weighed on Day 7, 14 and 28, and the growth rate was calculated. [ Result] The growth of mice had significant difference between the experiment groups and control group (P 〈 0.05), which indicated that the pST and liposome-encapsulated pST had growth-promoting effects in mice, and the liposome-encapsulated pST had sustained-release effects. [Condusion] The liposome-encapsulated pST can promote the growth of animal and its sustained-release peried is 7 d.
文摘This paper aims at assessing the evolutionist and creationist conceptions of Brazilian teachers. The work is developed within the framework of the European project BIOHEAD-CITIZEN (biology, health and environmental education for better citizenship), which takes into account that scientific knowledge and teachers' attitudes and values can influence the teaching practices. The large questionnaire BIOHEAD-CITIZEN, which was constructed to be applied in 19 countries in Europe, Africa and Middle East countries, was applied, in this study, to six groups of Brazilian teachers: primary school teachers, biology teachers and Portuguese language teachers and corresponding teachers-to-be. For this paper the answers to questions about evolution were used as dependent variables. Descriptive and multivariate analyses were carried out. Biology teachers and biology teachers-to-be gave more importance to the natural selection and the evolution process than the other groups of teachers. Comparing to the BIOHEAD-CITIZEN countries, the total Brazilian sample showed a higher percentage of creationist conceptions, particularly the Brazilian biology teachers and teachers-to-be. As discussed herein, this may not be an obstacle for teaching evolution as they accept both creationist and evolutionist concomitantly.
文摘This paper computed the newest impact solutions of the potentially dangerous asteroid (99942) Apophis based on 4,138 optical observations from March 15.10789 UTC (Universal Time Coordinated), 2004 to February 28.089569 UTC, 2014 and 20 radar observations from January 27, 2005 through March 15, 2013, as of June 20, 2014. Using the freely available the OrbFit software Package, this paper followed its orbit forward in the searching for close approaches with the Earth and possible impacts up to year 2116. With the different A2 non-gravitational parameter in the motion of the asteroid (99942) Apophis, this paper computed possible impact solutions using the JPL DE405 (Jet Propulsion Laboratory Development Ephemeris) and 25 additional massive perturbed asteroids. Additionally, this paper used weighing and selection methods adopted in the OrbFit software as prepared by the NEODyS (Near Earth Objects--Dynamical Side) Team. Moreover, this paper used method of computing the orbit of Apophis taking into account star catalog debiasing and an error model with assumed astrometric errors RMS (root mean square), deduced from the observational material of the given observatories. JPL's Sentry and NEODyS's CLOMMON2, two automatic monitoring systems routinely scanning for possible impacts in the next hundred years. Only for several dangerous asteroids presented results are computed with the non-gravitational parameters. This paper detected possible impacts of the asteroid (99942) Apophis only with the non-gravitational parameter, A2 〉 0. It was appeared that impacts in 2068, 2087, 2105 and in 2111 were possible only when Apophis rotated in prograde direction.
文摘An imported wine purchasing model for medium and small size enterprises is presented based on analytic hierarchy process after analyzing the current purchasing condition of medium and small size enterprise for wine importing. This model is feasible and practical. It will support and assist the purchasing strategy for the enterprise when importing wine within a certain scope and provide the reference to the enterprise for decision-making.